Alignment adjustment at the ball joint has been a desirable but difficult exercise. When the ball joint is carried in the spindle, caster, camber and steering angle (king-pin inclination) can be changed. Reversal of these mountings limits adjustment to camber since the actual pivot locations are fixed. Though not limited to such uses, most ball joint adjustment is to be found in rigid axle, usually four-wheel drive, vehicles.
Perhaps the most widely utilized example of such devices is that described in my U.S. Pat. No. 4,252,338. In this arrangement, a conventional, symmetrical ball joint bushing is removed and replaced with an offset and/or skewed bushing. The bushing is located with the offset oriented in a direction determined by the required alignment correction. Since the bushing is usually threaded, the depth of mounting of the bushing is controllable only to a portion of the thread pitch. Accordingly, ball joint preloaded, which is a function of the bushing position, is not precisely controllable. Instead, the bushing position is determined by alignment rather than preload consideration.
U.S. Pat. No. 4,231,588 discusses a structure using a socket portion fitted in a spindle which receives an outer sleeve which in turn both complementary fits the socket and fits the tapered ball joint stud. Thus, when the ball joint nut is secured on the stud, it bears upon the sleeve and pulls the stud into the sleeve. The tapered shape of the stud expands the sleeve to cause it to seize the socket and lock the structure. By way of drawbacks, the structure requires the alignment to be maintained in an unsteady manner as the nut is tightened, and the "locking" is by friction between two spherical surfaces, one concave and one convex. Such locking is at best marginal in view of the loads carried through the structure.